Valery Polyakov, the record holder for the longest flight into space, passes away

Astronaut Valeriy Polyakov, who set the record for the longest flight in space, has died at the age of 81. This is according to a Roscosmos statement released on Monday.

"Roskosmos State Corporation sadly reports the death of Valery Polyakov, Hero of the Soviet Union, Hero of Russia, USSR astronaut, holder of the world record for the longest flight into space (437 days)," the statement reads.

Polyakov completed two space missions. In total, he stayed in orbit for 678 days and 16 hours. Roscosmos noted that the astronaut's research helped prove that the human body is ready to travel not only to Earth orbit, but also to deep space.